David brooks



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@uitrit istrs atrut @fitta DAVID BROOKS, OF PHILADELPHIA, PENNSYLVANIA.

Letters Patent No. 69,622, dated October 8, 1867.

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T0 ALL IVI-IOM IT MAYCONCERN:

Be it known that I, DAVID BROOKS, of Philadelphia, Pennsylvanimhave invented certain Improvements in Insulators for Telegraph Wires; and I do hereby declare the following to be a full, clear, and exact description ofthe same. i

My invention relates to the construction ofinsulators for telegraph wires, the main feature of my inveu.- tion consisting of the combination, substantially as described hereafter', of a vessel or tube of blown glass with a telegraphic-wire insulator, so that amore perfect insulation may bc attained.

In order to enable others skilled in the art to make and use my invention, I will now proceed to describe its construction and operation, reference being had to the accompanying drawing, which forms a part of this specification, and in whichv Figures l and 2 are'sectional elevations of my improved insulator as it appears when partly completed.

Figure 3, an inverted sectional view of the insulator complete; and

Figures 4 and 5 modifications of my invention. i

In figs. I, 2, and 3, A is a cast-iron wire-holder, which consists of a stem, a, having at one end the usual A curved arms b b. B is a metal case, open at one end, and C is a vessel of blown glass, the opposite sides of. which are flattened, as shown in fig. 3. D is a hollow cylinder or band of glass, porcelain, or earthenwarc, and is of such a size as to surround the neck of the vessel C without being in contact therewith at any point. A band, x, pf paper or other fabric is cemented to the inside of the case B, a short distance from the open end of the same.- Melted sulphur is poured into the case, and the vessel C is inserted in the .position shown in figs. I and 2,the u-pper surface of the sulphur being above the lower edge of the paper band x. Melted parafine isv now poured on to the sulphur in t-he case, and the cylinder D is so adjusted that it will be secured in the position shown in fig. 2 by the hardened paraine. The remaining annular space between the cylinder D and the case B is then filled with melted sulphur. The stem a of the holder A is now introduced into the vessel C, and is secured by melted sulphur, with which the said vessel is partly filled, melted paraine being poured onto the top of the sulphur after the'latter has become hard. The case is now heated and then inverted, so 'that all the paraiine except that absorbed vby the sulphur, and that which remains in the annular portion m, iig. 3, between the cylinder D and the 'paper' handy, will escape. The case and its contents are then allowed to cool, after which parane is again poured into the vessel C, so as to` cover the surface of the sulphur in the same, and form a ring or belt, y', round the stem.l

I have found, after lengthened and repeated experiments, that blown glass'is a much more perfect insulat ing medium than glass pressed in a. mould, for the reason that the surface of pressed glass contains minuteA fissures, in which moisture or dust collects, and permits the escape of electric currents. I have also found that the .inner surface of a blown-glass vessel is much less liable yto collect and retain moisture than the outer surfaces of the same. By the substitution, therefore, of a blown-glass'vessel for the pressed or moulded' cup or cylinder of glass heretpfore employed, the wire-holder is much more perfectly insulated, while the amount of glass, and consequentlythe weignt of the insulator, is reduced. A tube, c, of blown glass, as shown in fig. 4,' may be substituted for the glass vessel illustrated in figs.` I, 2, and 3. A vessel of blown glass may be used in the manner illustrated in iig. 5, when it is desired to dispense with the case B and'wire-holder, the wire in this case being wrapped round the vessel, which is adjusted to the pin at in a manner clearly shown' 1n the drawing. The body mof'paratline contained within the annular recess y perfectly insulates the holder from the case, and the recess thus situated serves to retain the parailine in its place, even if it should be melted by the heat to which insulators are sometimes exposed. Dy the use of a detachable cylinder, D, the recess fort-he reception ofthe parafline may be formed after the vessel C has been introduced into the casing, the expense of so constructing thc case as to form a recess orreceptaclc for the paraine being thus avoided. i

I claim as my invention, and desire to secure by Letters Patent I. The combination, substantially as described, of a vesselor tube of blown glass with a tclegraphic-wiruA insulator, for the purpose described. l

2. A wire-holder, A, and case B, in combination with a tube or vessel, C, of blown glass, arranged between the holder and case, and insulated from both, substantially as :md for the purpose specified.

` 3. A 1'ecess,'y, arranged between the case B and holder A, and containing parafline for the purpose set fortha f1. A detachable cylinder, D,- mranged in respect to the holder, ense B, and vessel C, and insulated freni the salme, substantially as and fer the purpose set forh.

In testimony Whereofl'have signed my na'me to this specification in the presence eftwo subscribing witnesses.

DAVID BROOKS, Witnesses: Y Y

JOHN WHITE,

C. B. PRICE. 

